Object temperature adjusting system, control unit for adjusting object temperature, method of adjusting temperature of object, and signal-bearing medium embodying program of controller

ABSTRACT

An object temperature adjusting system includes an adjuster which adjusts a temperature of an object, and a controller which controls the adjuster to adjust the temperature of the object. The controller obtains a state function of an object temperature versus a temperature adjusting value using the object. The controller controls the adjuster using the temperature adjusting value.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to an object temperature adjusting system (e.g., a cooling system) of an object (e.g., an apparatus having a heat-generating unit), a controller for adjusting an object temperature, a method of adjusting temperature of an object, and a signal-bearing medium embodying a program of a controller. Exemplarily, the present invention relates to a temperature adjusting system (e.g., a fan control cooling system) which monitors the temperature of an object (e.g., a heat-generating unit).

2. Background Art

In a temperature adjusting object whose temperature changes (e.g., an apparatus having a heat-generating unit such as a computer equipped with an electronic component), a change of temperature of the object (e.g., a rise in the temperature the apparatus caused by the heat-generating unit) may destabilize operation or break the object (e.g., the apparatus). This may cause damage and thus should be avoided. Therefore, the object temperature is adjusted (e.g., the heat-generating unit is forcibly cooled by an airflow of a cooling fan or water. If the object needs heat, then the object is heated.). For example, a notebook computer includes a fan for cooling a heat-generating unit such as a processor and a fan controller (control unit).

Recently, the amount of heat generated in a processor largely increases and, for example, may exceed 100 W. However, high-density packaging to implement a reduction in wiring length accompanying a reduction in size of a housing and an increase in speed of signals becomes important for an apparatus, and thus the heat density is increasing at an accelerating pace. As for a dissipater, such as a heat sink, its dissipation area has not increased. On the contrary, the area is decreasing. Thus, to improve the cooling performance, the speed of flow of air is increased, e.g., the number of fan revolutions is increased, in the case of fan-cooling. As such, fan manufacturers are developing fans which can rotate at ever higher speeds.

An increased speed of a fan in turn increases the noise of an apparatus, and even may degrade the installation environment characteristics of the apparatus. More specifically, there may be imposed a constraint such as that the apparatus cannot be placed in a common office and can only be installed in a computer room. In the cooling design for a general apparatus, the apparatus is designed such that its processor can stably operate at the maximum temperature of the temperature range for an environment in which the apparatus is installed. Accordingly, for example, if an apparatus which must be placed in an environment at up to 40° C. is placed in an environment at 25° C., there is a margin of 15° C. One of the conventional fan control methods is a method of decreasing the number of fan revolutions using the temperature margin of the installation environment.

For example, a proposed fan temperature adjustable speed control is a method of reducing noise by lowering the number of fan revolutions when there is leeway in the temperature of a processor or the like. A temperature to be monitored is ideally the temperature of a processor. However, a conventional fan revolution number control method does not specify to what number to set the number of revolutions of a fan depending on what temperature a processor is. Actually, the relation between a temperature to be monitored and the number of fan revolutions is given by a straight line (e.g., linear).

FIG. 6 is a graph showing that the conventional relation between the temperature and the number of revolutions forms a straight line (linear function). The relation between the temperature and the number of fan revolutions should be set by a user. However, it is difficult even for a skilled engineer to estimate the relation between the temperature of a processor and the number of fan revolutions without using an actual apparatus. This is because the number of elements to be taken into consideration is large, and small errors in estimation accumulate to seriously upset a relational expression.

For this reason, monitoring of the processor temperature is not performed, but instead a method of monitoring the temperature of the installation environment of an apparatus and controlling the number of fan revolutions is adopted. However, this method does not use a system for controlling the number of fan revolutions so as to keep the temperature of the processor constant and optimizing both the reliability and noise.

Additionally, the amount of heat generated in a processor is not always that obtained at full power consumption. To perform finer fan control, for example, it may be ideal to directly monitor the temperature of the processor and perform fan control by feedback.

Such computer fan control cooling systems each of which monitors the temperature of a CPU (Central Processing Unit) serving as a heat-generating unit and cools the CPU by increasing or decreasing the number of fan revolutions by feedback on the basis of a difference from a preset temperature (target value) are proposed by Japanese Patent Laid-Open No. 2000-29574 and Japanese Patent Laid-Open No. 2004-302996.

The fan control cooling systems of Japanese Patent Laid-Open No. 2000-29574 and Japanese Patent Laid-Open No. 2004-302996 which each have a temperature monitoring function and perform feedback control, require prior input of the relation between the temperature of a processor and the number of fan revolutions. However, it is extremely difficult to use such systems in an actual apparatus. This is because the behavior of an airflow must be accurately tracked to estimate the wind speed caught by the processor, and the apparatus or processor must know the detailed structure of a card (e.g., an integrated circuit card) to be mounted. Even if the detailed structure can be analyzed by linking CAD (computer-aided design) and CAE (computer-aided engineering), a designer is required to have considerable skill and much time, to accurately predict a function of the temperature to a housing level of the apparatus and the wind speed.

In the fan control cooling system of Japanese Patent Laid-Open No. 2000-29574 as well, (1) the number of revolutions at a low temperature (Tmin) is determined to be expressed by (Rmin), the number of revolutions at a high temperature (Tmax) is determined to be expressed by (Rmax), and a straight line (linear function) is placed therebetween, as shown in FIG. 6.

SUMMARY OF THE INVENTION

However, it is impossible for a conventional fan control cooling system to actually perform feedback on the number of fan revolutions so as to keep a temperature constant. This is because the relation between the temperature of a processor and the number of fan revolutions theoretically does not form a straight line and approximately becomes a square root function.

As described above, a conventional object temperature adjusting system (e.g., fan control cooling system) as disclosed in Japanese Patent Laid-Open No. 2000-29574 is a system which monitors the temperature of the object (e.g., a processor) and applies feedback to the temperature adjusting value (e.g., the number of fan revolutions). A state function of the temperature and the temperature adjusting value (e.g., the number of fan revolutions) for feedback control is assumed to be a linear function, but is actually a nonlinear function. Therefore, even when this system is adopted, control cannot be performed unless the relation between the temperature and the temperature adjusting value (e.g., the number of fan revolutions) in an actual object (e.g., apparatus) is tracked. As a result, there cannot be provided an object (e.g., apparatus) having an optimum object temperature adjusting system (e.g., fan control cooling system).

In view of the foregoing and other exemplary problems, drawbacks, and disadvantages of the conventional techniques, it is an exemplary feature of the present invention to provide an object temperature adjusting system (e.g., a fan control cooling system, a water cooling system, a heater system, and so on), a control unit (controller) for adjusting an object temperature, a method of adjusting a temperature of an object, and a signal-bearing medium embodying a program of a controller.

For example, it is an exemplary feature of the present invention to provide a fan control cooling system with an optimized combination of a temperature and the number of fan revolutions. In addition, for example, it is an exemplary feature of the present invention to provide a fan control cooling system with an optimized combination of the temperature and noise by performing a fan revolution number control according to a state function obtained from an actual apparatus. For example, the state function may be obtained when feedback-controlling the number of fan revolutions using the temperature of a heat-generating unit.

The present invention may include an exemplary feature to (1) build a system which obtains a state function of the temperature adjusting value (e.g., the number of fan revolutions) versus the temperature of an object (e.g., a heat-generating unit) using an actual object (e.g., apparatus). The present invention may include an exemplary feature to (2) feedback-control the temperature adjusting value (e.g., the number of fan revolutions) using the obtained state function so as to keep the temperature constant.

The present invention provides an object temperature adjusting system, including an adjuster which adjusts a temperature of an object, and a controller which controls the adjuster to adjust the temperature of the object, the controller obtaining a state function of an object temperature versus a temperature adjusting value using the object, the controller controlling the adjuster using the temperature adjusting value.

The present invention also provides a control unit for adjusting an object temperature, including a controller which receives an input from an object whose temperature is adjustable by the controller, and which provides an output, based on a state function of the object temperature versus a temperature adjusting value, to an adjuster to adjust a temperature of the object. The controller obtains a state function of the object temperature versus the temperature adjusting value using the object.

The present invention also provides a method of adjusting temperature of an object, including obtaining a state function of the object temperature versus a temperature adjusting value using the object.

The present invention also provides a signal-bearing medium embodying a program of machine-readable instructions executable by a controller, the program causing the controller to perform a method described above.

The present invention also provides an object temperature adjusting system, including an adjuster which adjusts temperature of an object, and a controller which controls the adjuster to adjust the temperature of the object, the controller receiving an input from the object, and providing an output to the adjuster. The controller provides the output based on a nonlinearity of the temperature and a characteristic of the adjuster.

The present invention also provides an object temperature adjusting control unit, including a controller which receives an input from an object whose temperature is adjustable by the controller, and which provides an output to an adjuster to adjust a temperature of the object. The controller provides the output based on a nonlinearity of the temperature and a characteristic of the adjuster.

The present invention also provides a method of adjusting temperature of an object, including receiving an input from the object whose temperature is adjustable, and providing an output based on a nonlinearity of the temperature and a characteristic of an adjuster that adjusts the temperature of the object, to the adjuster.

EXEMPLARY ADVANTAGE OF THE INVENTION

The present invention may produce many exemplary advantages.

For example, a first exemplary advantage may be that a state function of the temperature adjusting value (e.g., the number of fan revolutions) versus the temperature of an object (e.g., a heat-generating unit) may be obtained (e.g., obtained automatically) using an actual object (e.g., apparatus). The state function may be obtained accurately and easily without the need for special knowledge and advanced skill or without prior careful evaluation, for example.

A second exemplary advantage may be that feedback may be applied and the temperature adjusting value (e.g., the number of fan revolutions) may be applied using the function so as to keep the temperature of the object (e.g., the heat-generating unit) constant. For example, the object (e.g., heat-generating unit) may be operated at an optimum temperature. This may ensure the reliability for the temperature of the object (e.g., the apparatus) and, for example, in the case of a fan cooling, this may suppress noise generation to a minimum level commensurate with the operating environment of the object (e.g., the apparatus). Thus, this may optimize the installation environment characteristics of the object (e.g., the apparatus).

BRIEF DESCRIPTION OF THE DRAWINGS

The novel and exemplary features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as other exemplary features and advantages thereof, will be best understood by reference to the detailed description which follows, read in conjunction with the accompanying drawings, wherein:

FIG. 1 is an exemplary overview of an object temperature adjusting system (e.g., fan control cooling system 4) which monitors the temperature of the object (e.g., processor 2) and performs an adjuster control (e.g., fan 1 control) by feedback according to an exemplary embodiment of the present invention;

FIG. 2 is an exemplary conceptual graph showing how the temperature of processor 2 serving as an exemplary object to be adjusted (e.g., cooled) changes with a wind speed (i.e., the correlation between the temperature and the wind speed);

FIG. 3 is an exemplary graph showing an exemplary state function of the present invention;

FIG. 4 is an exemplary flow chart of the object temperature adjusting system (e.g., fan control cooling system 4) having a temperature monitoring function according to the present invention;

FIG. 5 is an exemplary flow chart showing another example in which an exemplary state function is obtained in the object temperature adjusting system (e.g., fan control cooling system 4) having a temperature monitoring function according to the present invention; and

FIG. 6 is an exemplary graph showing that an exemplary conventional relation between a temperature and the number of revolutions forms a straight line (linear function).

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The present invention provides an object temperature adjusting system, including an adjuster which adjusts a temperature of an object, and a controller which controls the adjuster to adjust the temperature of the object, the controller obtaining a state function of an object temperature versus a temperature adjusting value using the object, the controller controlling the adjuster using the temperature adjusting value.

The controller may measure the object temperature with respect to the temperature adjusting value, and the controller may calculate the state function by the object temperature and corresponding the temperature adjusting value thereto.

The controller may calculate the state function by approximating the state function by a non-linear function.

The object temperature adjusting system may further include a memory, the controller registering the state function in the memory.

The controller may start monitoring temperature of the object and controlling the adjuster by using the temperature adjusting value in accordance with the state function.

The controller may perform a feedback operation so as to keep the temperature of the object constant.

The controller may measure the object temperature with respect to the temperature adjusting value during the feedback operation.

The controller may update the state function periodically.

The controller may update the state function by calculating the state function by the object temperature and corresponding the temperature adjusting value thereto during the feedback operation.

The object may include a device which includes a heat-generating unit, the adjuster may include a fan which cools the heat-generating unit in accordance with the temperature adjusting value, and the temperature adjusting value may include a number of fan revolutions.

The device may include an electronic equipment.

The device may include a computer which includes a processor as a heat-generating unit.

The present invention also provides a control unit for adjusting an object temperature, including a controller which receives an input from an object whose temperature is adjustable by the controller, and which provides an output based on a state function of the object temperature versus a temperature adjusting value to an adjuster to adjust a temperature of the object. The controller obtains a state function of the object temperature versus the temperature adjusting value using the object.

The present invention provides a method of adjusting temperature of the object, including obtaining a state function of the object temperature versus a temperature adjusting value using the object.

The method may further include adjusting the object temperature in accordance with the temperature adjusting value.

The obtaining of the state function may include measuring the object temperature with respect to the temperature adjusting value, and calculating the state function by the object temperature and corresponding the temperature adjusting value thereto.

The obtaining of the state function may include approximating the state function by a non-linear function.

The method may further include registering the state function in a memory.

The method may further include monitoring a temperature of the object, and adjusting the temperature of the object by using the temperature adjusting value in accordance with the state function.

The method may further include performing a feedback operation so as to keep constant the temperature of the object.

The feedback operation may include measuring the object temperature with respect to the temperature adjusting value during the feedback operation.

The method may further include updating the state function periodically.

The updating may include calculating the state function by the object temperature with respect to the temperature adjusting value during the feedback operation.

The method may further include providing a device which includes a heat-generating unit as the object, providing a fan which cools the heat-generating unit in accordance with the temperature adjusting value, and providing the temperature adjusting value which includes a number of fan revolutions.

The method may further include providing an electronic equipment as the device.

The method may further include providing a computer which includes a processor as the heat-generating unit.

The present invention also provides a signal-bearing medium embodying a program of machine-readable instructions executable by a controller, the program causing the controller to perform a method described above.

The present invention also provides an object temperature adjusting system, including an adjuster which adjusts temperature of an object, and a controller which controls the adjuster to adjust the temperature of the object, the controller receiving an input from the object, and providing an output to the adjuster. The controller provides the output based on a nonlinearity of the temperature and a characteristic of the adjuster.

The present invention also provides an object temperature adjusting control unit, including a controller which receives an input from an object whose temperature is adjustable by the controller, and which provides an output to an adjuster to adjust a temperature of the object. The controller provides the output based on a nonlinearity of the temperature and a characteristic of the adjuster.

The present invention also provides a method of adjusting temperature of an object, including receiving an input from the object whose temperature is adjustable, and providing an output based on a nonlinearity of the temperature and a characteristic of an adjuster that adjusts the temperature of the object, to the adjuster.

As described above, for example, it may be extremely difficult to computationally or theoretically determine a state function representing the relation of the temperature adjusting value (e.g., the number of fan revolutions) to the temperature of an object (e.g., a heat-generating unit).

An exemplary embodiment of the present invention is an object temperature adjusting system (e.g., a fan control cooling system 4) having a temperature monitoring function in an object (e.g., a computer) such that the temperature of an object to be adjusted (e.g., to be cooled), such as a processor, is correlated with the speed of a fan (e.g., the number of revolutions of the fan) and which may be so optimized as to keep the temperature constant using the obtained state function, for example. Also, for example, the correlation may be automatically calculated using an actual apparatus.

The embodiment will be explained in detail with reference to the drawings.

[Exemplary Configuration of Components]

FIG. 1 shows an exemplary overview of an object temperature adjusting system (e.g., fan control cooling system 4) which monitors the temperature of the object (e.g., processor 2) and performs an adjuster control (e.g., fan 1 control) by feedback according to an exemplary embodiment of the present invention.

The object temperature adjusting system (e.g., fan control cooling system 4) having the function of monitoring the temperature of an object (e.g., processor 2) is shown in FIG. 1. Reference numeral 2 may be an object whose temperature may be adjusted (e.g., may be cooled) such as processor 2. The object to be adjusted (e.g., to be cooled) may be an LSI (Large Scale Integration) or IC (Integrated Circuit) other than a processor. Reference numeral 1 may be a temperature adjuster (e.g., fan 1) that adjusts (e.g., cools) the temperature of processor 2 serving as the object to be adjusted (e.g., to be cooled) to a stable operating temperature.

The temperature adjuster (e.g., fan 1) may include an analog controller function, a function of changing the temperature adjusting value (e.g., the number of fan revolutions) by, e.g., applying a voltage from the outside of the temperature adjuster (e.g., fan 1), or, for example, the temperature adjuster (e.g., fan 1), which may include a function which can change the number of revolutions by changing the driving voltage itself of the temperature adjuster (e.g., fan 1).

Alternatively, the temperature adjuster (e.g., fan 1) itself may not need to include these functions. The temperature adjuster (e.g., fan 1) may adopt a PWM (pulse-width modulation) method of changing the number of revolutions by changing a frequency at which the driving voltage of the fan is applied.

Reference numeral 3 may be a controller (e.g., control IC 3) according to the present invention, serving as a control unit of object temperature adjusting system (e.g., fan control cooling system 4) having the temperature monitoring function. For example, IC 3 may execute a program stored in a signal-bearing medium (e.g., a memory: not shown) to control the object temperature adjusting system (e.g., fan control cooling system 4).

For example, in the object temperature adjusting system, an object's temperature may be adjustable by the controller. The controller (e.g., control IC 3) may obtain a state function of an object temperature versus a temperature adjusting value using the object (e.g., processor 2). The controller (e.g., control IC 3) may control an adjuster (e.g., fan 1) using the temperature adjusting value (e.g., the number of revolutions). Then, the adjuster may adjust the object temperature.

In another exemplary aspect, the object temperature adjusting controller (e.g., control IC 3) may receive an input from the object (e.g., processor 2) whose temperature is adjustable by the controller, and may provide an output to the adjuster (e.g., fan 1) to adjust a temperature of the object (e.g., processor 2). The controller may provide the output based on a nonlinearity of the temperature (described later) and a characteristic of the temperature adjuster.

At the time of monitoring the temperature of an LSI or the like, it is possible that the temperature may be measured using a PN-junction diode (thermal diode) formed inside the LSI for temperature measurement, for example. This can be derived from a theoretical expression saying that the value of the voltage across the anode and cathode obtained when a constant current is supplied to the thermal diode becomes a function of temperature. As described above, the temperature adjusting value (e.g., the number of fan revolutions) can be controlled by adopting the analog controller, PWM method, or the like.

The specific configuration of components will be further explained.

FIG. 2 is an exemplary conceptual graph showing how the temperature of processor 2-serving as an exemplary object to be adjusted (e.g., cooled) changes with a wind speed (i.e., the correlation between the temperature and the wind speed).

Heat generated in the processor exits from the surface of the processor, passes through a dissipater or the like, and is finally dissipated to ambient air by heat transfer. It is experimentally or theoretically known that heat transfer is not given by a linear function of the wind speed of air, but is inversely proportional to, e.g., the 0.5- to 0.6-th power of the wind speed.

More specifically, in an area where the wind speed is low, the temperature of the processor largely reacts to a change in wind speed. On the other hand, in an area where the wind speed is high, the temperature of the processor reacts only slowly to a change in wind speed. Since in a commonly used area, the wind speed is proportional to the number of fan revolutions, the wind speed can be replaced with the number of fan revolutions.

Consequently, a state function should be considered to control the number of fan revolutions so as to keep the temperature of the processor constant.

FIG. 3 is a graph showing an exemplary state function of the present invention.

The state function indicated by a solid line in FIG. 3 can be logically derived from the graph of FIG. 2. Controlling the number of fan revolutions using the state function means, in concrete terms, measuring an actual temperature and determining the number of fan revolutions to be prescribed on the basis of the state function using a deviation from a temperature target value. In the state function shown in FIG. 3, the number of fan revolutions should be largely changed to stabilize the temperature of the processor at a target value Ta on a lower temperature side, while the number of fan revolutions need not be changed much to stabilize the temperature at a target value Tb on a higher temperature side.

Accordingly, if the relation between the temperature and the number of revolutions is given by a linear function without regard to the above-described relation (e.g., the number of fan revolutions is changed greatly at a target value Tb on a higher temperature side, while the number of fan revolutions need not be changed much), the number of fan revolutions becomes out of control. The revolution of the fan causes “chattering”, i.e., rotational waves, which leads to the instability of control operation or more specifically the instability of the temperature.

As for the object temperature adjustment system (e.g., the fan, control cooling system 4) of this exemplary embodiment, the relation between the temperature of processor 2 or the like and the temperature adjusting value (e.g., the number of fan revolutions) can be made to approximate to an exponential function (e.g., a square root function) in the actual apparatus, as illustrated by the solid line.

As described above, in the exemplary embodiment, for example, (1) since the temperature adjusting value (e.g., the number of fan revolutions) may be controlled using a state function of the temperature adjusting values (e.g., the number of fan revolutions) versus the temperature of an object (e.g., a heat-generating unit) in an actual apparatus, it may be so controlled as to keep the temperature constant at a specified value. For this reason, for example, (2) there may be provided a system which optimizes the installation environment characteristics such as noise while ensuring the reliability of the apparatus.

[Operation]

FIG. 4 is an exemplary flow chart of fan control cooling system 4 having a temperature monitoring function according to the present invention. The graph in FIG. 4 corresponds to the graph of FIG. 2.

When a fan is rotated at a certain set wind speed, a thermal equilibrium state is reached after a lapse of a certain period of time. Since in this state, a temperature becomes constant and stable, the temperature at this tine is measured. More specifically, in the operating environment of an apparatus, the number of revolutions of the fan and the temperature of a processor are measured at a certain time. The timing of this measurement is arbitrarily set. For example, there is known a method of performing triggering at the time of, e.g., the start-up of the apparatus, and the like. Triggering may be performed with precise timing before the apparatus executes a program or the like (Step 1).

In measurement of the temperature of the processor, the temperature is measured while the number of fan revolutions is changed. As methods of changing the number of fan revolutions, there are available an analog controller method of changing the number of revolutions by applying a voltage to the fan itself, a PWM method of implementing the change by changing the frequency at which the driving voltage of the fan is applied, and the like. An explanation will be given by taking the PWM method as an example. The change is implemented by turning on and off the driving voltage of the fan at regular intervals. If the ON tine is set to 30%, and the OFF time is set to 70%, then a Duty ratio becomes 30%.

As shown in the graph of FIG. 4, the Duty ratio is made to differ among at least three points R₁, R₂, and R₃, and temperatures T₁, T₂, and T₃ of the processor corresponding to the points are measured. The temperature of the processor can be measured by measuring the voltage across the anode and cathode of a thermal diode formed inside the processor when a constant current is applied to the diode. For example, assume that the processor is one which is commonly used in a PC or the like. Letting V_(f1) be a voltage at 100 μA, and V_(f2) be a voltage at 10 μA, the following equation is obtained (Step 2). T[K]=5×(V _(f1) −V _(f2))   (1)

The correlation between the temperature and the number of fan revolutions is calculated using the plurality of measurement points (e.g., the correlation between the temperature and the number of fan revolutions is approximated by a nonlinear function). For, example, the temperature may be made to approximate the exponential function (e.g., the inverse of the square root of the speed, i.e., the number of fan revolutions). For example, T=α/Rˆn+β/Rˆ( n−1)+γ/Rˆ(n−2)+   (2)

In the exemplary expression (2), R means the number of fan revolutions. If n=½ in the above expression (i.e., the first term becomes the inverse of the square root of the number of fan revolutions), the correlation can be calculated using at least three measurement points. A state function can be obtained from the correlation (Step 3).

The state function may be registered in a memory inside an IC or the like (Step 4). The state function in the memory may be referred to while monitoring the temperature of processor 2. With this operation, it may become possible to control the number of fan revolutions so as to keep the temperature constant (i.e., the controller performs a feedback operation so as to keep the temperature of the object (e.g., processor 2) constant.) (Step 5).

The state function is a function typically fixed for each apparatus. If conditions are changed from those when the correlation between the temperature and the number of fan revolutions is measured, then the state function should be obtained again. For example, a case wherein a heat-generating component such as a hard disk drive (HDD) mounted on the windward side of the processor is lost corresponds to this case. To cope with this, there can be considered a method of changing the state function at regular intervals, changing the number of fan revolutions, and measuring the temperature again, and the like.

Another example wherein a state function is obtained will be explained next.

FIG. 5 is an exemplary flow chart showing another example in which an exemplary state function is obtained in the object temperature adjusting system (e.g., fan control cooling system 4) having a temperature monitoring function according to the present invention.

This example may be a method of operating an actual device as the apparatus using the state function obtained by the method shown in FIG. 4 and updating the state function using data obtained during operation (e.g., the controller (e.g., control IC 3) measures the object (e.g., processor 2) temperature with respect to the temperature adjusting value (e.g., the number of fan revolutions) during the feedback operation and updates the state function periodically) (Step 6). Assume that data of temperatures and the numbers of revolutions on which feedback has been performed are accumulated (Step 7) and that a new state function is obtained after a certain period of time passed and a certain amount of data is held (Step 8, “Yes”). In this case, a state function may be updated in a short period of time even without time for temperature measurement (Step 9).

In FIG. 5, the state function need not be obtained after measurement at a plurality of points as in the above example. The state function can be obtained by accumulating data of points during feedback control on the number of revolutions so as to keep a temperature constant (Tset).

The case of a computer whose heat-generating unit is a processor has been explained above as an example of the object temperature adjusting system (e.g., fan control cooling system 4) of the present invention. However, the present invention can also be applied to electronic equipment which cools its heat-generating unit with a fan or common equipment such as an optical device which cools the light source of its heat-generating unit with a fan.

While this invention has been described with reference to exemplary embodiments, this description is not intended as limiting. Various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon taking description as a whole. It is, therefore, contemplated that the appended claims will cover any such modifications or embodiments as fall within the true scope of the invention.

While the exemplary embodiments above have been described in a relatively warm/hot environment in which the temperature is monitored to reduce the same to prevent damage to the object, as evident to one of ordinary skill in the art, taking the present application as a whole, the invention can be applied in a relatively cool/cold environment in which the temperature is monitored to increase the same to prevent damage to the object.

Further, the inventor's intent is to encompass all equivalents of all the elements of the claimed invention even if the claims are amended during prosecution.

This application is based on Japanese Patent Application No. 2005-011591 filed on Jan. 19, 2005 and including specification, claims, drawings and summary. The disclosure of the above Japanese Patent Application is incorporated herein by reference in its entirety. 

1. An object temperature adjusting system, comprising: an adjuster which adjusts a temperature of an object; and a controller which controls said adjuster to adjust said temperature of said object, said controller obtaining a state function of an object temperature versus a temperature adjusting value using said object, said controller controlling said adjuster using said temperature adjusting value.
 2. The object temperature adjusting system according to claim 1, wherein: said controller measures said object temperature with respect to said temperature adjusting value; and said controller calculates said state function by said object temperature and corresponding said temperature adjusting value thereto.
 3. The object temperature adjusting system according to claim 1, wherein: said controller calculates said state function by approximating said state function by a non-linear function.
 4. The object temperature adjusting system according to claim 1, further comprising: a memory, said controller registering said state function in said memory.
 5. The object temperature adjusting system according to claim 1, wherein: said controller starts monitoring temperature of said object and controlling said adjuster by using said temperature adjusting value in accordance with said state function.
 6. The object temperature adjusting system according to claim 1, wherein: said controller performs a feedback operation so as to keep said temperature of said object constant.
 7. The object temperature adjusting system according to claim 6, wherein: said controller measures said object temperature with respect to said temperature adjusting value during said feedback operation.
 8. The object temperature adjusting system according to claim 1, wherein: said controller updates said state function periodically.
 9. The object temperature adjusting system according to claim 6, wherein: said controller updates said state function by calculating said state function by said object temperature and corresponding said temperature adjusting value thereto during said feedback operation.
 10. The object temperature adjusting system according to claim 1, wherein: said object comprises a device which includes a heat-generating unit; said adjuster includes a fan which cools said heat-generating unit in accordance with said temperature adjusting value; and said temperature adjusting value includes a number of fan revolutions.
 11. The object temperature adjusting system according to claim 10, wherein: said device comprises an electronic equipment.
 12. The object temperature adjusting system according to claim 10, wherein: said device comprises a computer which includes a processor as a heat-generating unit.
 13. A control unit for adjusting an object temperature, comprising: a controller which receives an input from an object whose temperature is adjustable by said controller, and which provides an output based on a state function of said object temperature versus a temperature adjusting value to an adjuster to adjust a temperature of said object, wherein said controller obtains a state function of said object temperature versus said temperature adjusting value using said object.
 14. A method of adjusting temperature of an object, comprising: obtaining a state function of said object temperature versus a temperature adjusting value using said object.
 15. The method of adjusting temperature of said object according to claim 14, further comprising: adjusting said object temperature in accordance with said temperature adjusting value.
 16. The method of adjusting temperature of said object according to claim 14, wherein said obtaining said state function includes: measuring said object temperature with respect to said temperature adjusting value; and calculating said state function by said object temperature and corresponding said temperature adjusting value thereto.
 17. The method of adjusting temperature of said object according to claim 14, wherein said obtaining said state function includes: approximating said state function by a non-linear function.
 18. The method of adjusting temperature of said object according to claim 15, further comprising: registering said state function in a memory.
 19. The method of adjusting temperature of said object according to claim 14, further comprising: monitoring a temperature of said object; and adjusting said temperature of said object by using said temperature adjusting value in accordance with said state function.
 20. The method of adjusting temperature of said object according to claim 14, further comprising: performing a feedback operation so as to keep constant said temperature of said object.
 21. The method of adjusting temperature of said object according to claim 20, wherein said feedback operation includes: measuring said object temperature with respect to said temperature adjusting value during said feedback operation.
 22. The method of adjusting temperature of said object according to claim 21, further comprising: updating said state function periodically.
 23. The method of adjusting temperature of said object according to claim 22, wherein said updating includes: calculating said state function by said object temperature with respect to said temperature adjusting value during said feedback operation.
 24. The method of adjusting temperature of said object according to claim 23, further comprising: providing a device which includes a heat-generating unit as said object; providing a fan which cools said heat-generating unit in accordance with said temperature adjusting value; and providing said temperature adjusting value which includes a number of fan revolutions.
 25. The method of adjusting temperature of said object according to claim 24, further comprising: providing an electronic equipment as said device.
 26. The method of adjusting temperature of said object according to claim 24, further comprising: providing a computer which includes a processor as said heat-generating unit.
 27. A signal-bearing medium embodying a program of machine-readable instructions executable by a controller, said program causing said controller to perform a method of claim
 14. 28. An object temperature adjusting system, comprising: an adjuster which adjusts temperature of an object; and a controller which controls said adjuster to adjust said temperature of said object, said controller receiving an input from said object, and providing an output to said adjuster, wherein said controller provides said output based on a nonlinearity of said temperature and a characteristic of said adjuster.
 29. An object temperature adjusting control unit, comprising: a controller which receives an input from an object whose temperature is adjustable by said controller, and which provides an output to an adjuster to adjust a temperature of said object, wherein said controller provides said output based on a nonlinearity of said temperature and a characteristic of said adjuster.
 30. A method of adjusting temperature of an object, comprising: receiving an input from said object whose temperature is adjustable; and providing an output based on a nonlinearity of said temperature and a characteristic of an adjuster that adjusts said temperature of said object, to said adjuster. 